Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan

About: Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan is a education organization based out in Dnipro, Ukraine. It is known for research contribution in the topics: Track (rail transport) & Bogie. The organization has 736 authors who have published 655 publications receiving 1468 citations. The organization is also known as: Institute of Railway Transport Engineers.

Production of weldments from sintered titanium alloys

Abstract: Purpose. Limited application of details from powder titanium alloys is connected with the difficulties in obtaining of long-length blanks, details of complex shape and large size. We can solve these problems by applying the welding production technology. For this it is necessary to conduct a research of the structure and mechanical properties of welded joints of sintered titanium alloys produced by flash welding. Methodology. Titanium industrial powders, type PT5-1 were used as original substance. Forming of blanks, whose chemical composition corresponded to BT1-0 alloy, was carried out using the powder metallurgy method. Compounds were obtained by flash welding without preheating. Microstructural investigations and mechanical tests were carried out. To compare the results investigations of BT1-0 cast alloy were conducted. Findings. Samples of welded joints of sintered titanium blanks from VT1-0 alloy using the flash butt welding method were obtained. During welding the microstructure of basic metal consisting of grains of an a-phase, with sizes 40...70 mkm, is transformed for the seam weld and HAZ into the lamellar structure of an a-phase. The remaining pores in seam weld were practically absent; in the HAZ their size was up to 2 mkm, with 30 mkm in the basic metal. Attainable level of mechanical properties of the welded joint in sintered titanium alloys is comparable to the basic metal. Originality . Structure qualitative changes and attainable property complex of compounds of sintered titanium alloys, formed as a result of flash butt welding were found out. Practical value . The principal possibility of high-quality compounds obtaining of sintered titanium alloys by flash welding is shown. This gives a basis for wider application of sintered titanium alloys due to long-length blanks production that are correspond to deformable strand semi finished product.

Derivative of set measure functions and its application (theoretical bases of investment objectives)

Abstract: Purpose . It is necessary to develop the theoretical fundamentals for solving the investment objectives presented in the form of set function as vector optimization tasks or tasks of constrained extremum. Methodology . Set functions and their derivatives of measure are used as research of investment objectives. Necessary condition of set function minimum is proved. In the tasks for constrained extremum the method of Lagrange is used. It is shown that this method can also be used for the set function. It is used the measure for proof, which generalizes the Lebesgue measure, and the concept of set sequence limit is introduced. It is noted that the introduced limit over a measure coincides with the classical Borel limit and can be used in order to prove the existence of derivative from set function over a measure on convergent of sets sequence. Findings . An algorithm of solving the investment objective for constrained extremum in relation to investment objectives was offered. Originality . Scientific novelty lies in the fact that in multivariate objects for constrained extremum one can refuse from immediate enumeration. One can use the proposed algorithm of constructing (selection) of options that allow building a convex linear envelope of Pareto solutions. This envelope will let the person who makes a decision (DM), select those options that are "better" from a position of DM, and consider some of the criteria, the formalization of which are difficult or can not be described in mathematical terms. Practical value . Results of the study provide the necessary theoretical substantiation of decision-making in investment objectives, when there is a significant number of an investment objects and immediate enumeration of options is very difficult on time costs even for modern computing techniques.

Wastewater treatment of industrial enterprises by the natural metals

Abstract: Purpose. The paper deals with the galvanic coupling effect (time of treatment and other factors) on the removal of oil, synthetic surface active substances (SSAS), chromium, etc. from waste process solutions used in metalworking. It presents an overview of wastewater treatment technologies from heavy metal ions based on physicochemical processes. Methodology . To restore hexavalent chlorine to trivalent, authors decided to use the existing averager of acid-alkaline effluents as a kind of galvanic coagulant, for which it was filled with iron turnings and crushed coke. Findings. Authors researched wastewater of the electrotechnical industry and highlighted sorption methods for their purification with the use of coagulants, ion exchange. They considered a new galvanocoagulation method for purification from heavy metal (HM) ions (arsenic, chromium, non-ferrous metals), as well as petroleum products and organic substances dissolved in water. Permissible values of the quality indicators of wastewater and water in reservoirs are given. The classification of heavy metal groups according to the degree of toxic effect is presented. Their influence on the human body is considered. The use of the «LOTOS» reactor in the technological process of electroplatings wastes cleaning allows: to process them in a single stream, to abandon special reagents for cleaning effluents from hexavalent chromium and cyanides, to exclude the need for acidification of effluents, to reduce the use of alkaline reagents up to complete rejection of them, to reduce the equipment rate and number of production personnel (their main function is to purify solutions containing up to 1 g/dm 3 of hexavalent chromium. The reactor consists of unified modules, mounted in a single frame. Originality. On the basis of experimental research work, it was established possibility in principle of treatment of all liquids under research by the galvanocoagulation method. The method consists in contacting of wastewater simultaneously with copper and steel shavings (scrap) without using an external source of electric current. Practical value . The article highlights the topical issues of wastewater treatment from salts of heavy metals, which is necessary for sanitary and ecological purposes. We propose modern energy-saving and low-energy-consuming simple methods, such as the galvanic technique. The modern plant is widely used in industry, electroplating and metalware production. The described methods have a number of positive properties in the economic and energy relations. Salts of heavy metals are dangerous pollutants for both sewage and drinking water. Therefore, water treatment is a very important problem in the field of the environment of our country and abroad. The cleaning effect is achieved within 95 ... 98%.

Human inactivity in the context of subject’s identity problem

Abstract: The subject of article is analyze of essence postmodern understanding of human; finding relationship with personal identity and inactivity; accentuation on existential aspects of this relation; to investigate the alternatives to classical and pluralistic conceptions of subject’s identity. Scientific novelty of received results consists in a discovery of the relationship with human inactivity and personal identity. Results: the author has demonstrated that the conception of the subject and its identity in nowadays is very indeterminate. In particular, we can keep watching some contradiction between the interpretations of the subject as an amount of the identifications and statement as a basic ground of human his Self-being. In the context of this contradiction the author has demonstrate the relation with personal identity and human inactivity. Inactivity had understand how subject’s self-alienation and his self-identification with situational social roles and functions. This self-alienation leading to the perversion of true agency (doing), that must be direct on the own being. Grave cause of human inactivity is personal identity, that obstructing communicative, mental and practical agency. Therefore, how the alternative of classical and pluralistic conceptions of identity is the special form of identity, that ground on the subject’s Selfhood – being-in-world.

Issues of organizing the passenger transportation on us railways

Abstract: Purpose. The paper focuses on a study of the US railway transport organization management during passenger transportation. Methodology. Studies were carried out on the basis of the analysis of literature sources and reporting data on passenger transportation in the USA. Findings . Negative trends in the work of the passenger complex of the Ukrainian railways are the slowdown in the volumes of transportation, the progressive aging of the rolling stock and the overall activity running at a loss for Ukrzaliznytsia. In this regard, the actual task for domestic rail transport is the implementation of industry reforms. Therefore, the paper presented the study of the experience of organizing the passenger transportation on US railways, whose peculiarity is the extremely high degree of competition between modes of transport. As a result of the conducted analysis for working conditions of the US and Ukrainian railways, the general conditions for the functioning of the railways in both countries connected with passenger transportation securing have been established. It was found that general condition for execution of railway passenger transportation for the United States and Ukraine is the subsidization of this activity and combined use of infrastructure for the freight and passengers’ transportations. In this connection, when developing approaches to reforming the passenger economy of Ukraine's railways, it is advisable to use the experience of the United States in assessing the social effectiveness of rail transport, the impact of passenger transportation on the conditions of freight trains handling, and combined use of railway infrastructure by freight and passenger companies. Originality. The author determined the general trends in the development of passenger railway transportation in the US and Ukraine. Practical value . The resulted methods of organizing the operation of the US railway passenger transportation complex can be adapted to solve problems in the development of passenger transportation on the Ukrainian railways.